Variable-speed driving.



No. 840,721. PATENTED JAN. 8, 1907. V. O. STROBEL & A. B. HOGREBE.

VARIABLE SPEED DRIVING.

APPLICATION IIL ED JAN.20. 1905.

2 SHEETSSHEET 1.

PATENTED JAN. 8, 1907.

v.0. STROBBL & A. E. HOGREBE.

VARIABLE SPEED DRIVING. APPLICATION FILED JAN. 20. 1905.

2 SHEETS-SHBET 2.

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UNITED STATES PTENT OFFICE VICTOR O. STROBEL AND ARTHUR E. HOGREBE-OF PHILADELPHIA, PENNSYLVANIA, ASSIGNORS TO NILES-BEMENT-POND COMPANY,

OF J ERSEY CITY, NEW JERSEY.

IVAREAELE-SPEED DRWBNG.

Specification of Letters Patent.

Patented 8'an..8, 1907.

Application filed January 20, 1905. Serial No. 241.965.

.To all whom it may concern:

Be it known that we, Vroron O. STROBEL and ARTHUR E. HOGREBE, of Philadelphia,

State of Pennsylvania, have invented cerfeatures of patentable novelty then set forth in the claims.

F i re 1 is a plan view of a machine, to whic the invention has been applied. Figs. 2, 3, and i are diagrammatic views showing the different hases and combinations for securing varia le-speed conditions. Fig. 5 is a development of the cylindrical controller 3 shown in top view in Fig. 1.

A plurality of electric machines (preferably two) are employed to variably drive the moving member of the machine. Under certain running conditions both magnetoelectric machines act as electric motors, while under other conditions of variablespeed driving one or more of the electric machines is converted from a motor to a enerator, as will hereinafter be described. hese electric-machines are preferably com pound-wound and in series parallel.

The machine selected in this instance to illustrate a concrete application of the invention has a table, platen, or bed 1, reciprocating upon a frame 2. The frame is provided with a controller 3, having a tappetarm 3' and adapted to perform the hereinafter-described switching operations. The

controller is actuated by contacts 4% on the tahis 1 engaging tappet-arm 3. The armatureshafts of the electric machines 8 and 9 are referably provided with inions 5 and are ocated at each side of t e power-shaft 6. Shaft 6 has a gear 7 meshing with both pinions 5. Other known means of connecting the electric machines may of course be employed.

it will be understood that all the herein-' after-described makes and breaks in the electrical connections are or may be made automatically by the controller-switch 3.

Some of the adjustments of the circuits or the resistances are or may, however, be made manuall In the switch development shown in Fig. 5

manual provision may be made for adjusting the several shunt fields and rheostatsor resistances. Theseveralphasesof thevariablespeed adjustment hereinafter referred to are, however, performed automatically. The shunt fields and the various resistances may also-be controlled automatically.

12 to 23, inclusive, are the contact-fingers of the controller 3.

24 to 31, inclusive, are the controller-drum contacts for the forward speeds, and 32 to 39, inclusive, the reverse-speed drum-contacts.

40 to 45,, inclusive, are the forward-speed connections of the motors, and 4:6 to 51, inclusive, are the reverse-speed connections to the motors. The three series of connections corresponding to the three. phases of variation forward and reverse are shown at 52, 53, and 54 for the forward movements and at 55, 56, and 57 for the reverse movements.

52 and 55 are respectively the forward and reverse connections when the motors are in series, 53 and 56 when the motors are in parallel, and 5 and 57 when one of the motors is converted into a generator in series with the other motor and in series with the generatorsupply of current to the line. The connections, for instance, when the first phase forward-speed connection 52 is on and the m0- tors in series may be traced through the line to field F, contacts 45 52 44 28 16 27 15 to armature A, and thence to contacts 1e 26 I 29 17 43 52 42 3O 18 25 13 to armature A,

and thence to contacts 12 24 31 19 41 52 4O 46 to series field F to com lets the circuit. The other connections can e readily traced and need not be one into in detail. The several phase varia le-speed regulation is antomatically effected by the mechanical ma chine-contacted 4 at either side of the controller tap et-arm 3 on the drum-shaft en gaging sai arm and performing the several switching. operations.

In diagram Fig. 2 is illustrated the first phase or the lower range of variable speed driving of machines. Here both electric machines 8 and 9 run as motors; Themotors are compound-wound. The fields F and the armatures A A of the motors are connected in series with an adjustable resistance 10. and 11. The shunts S S are connected in parallel. The rheostat R is in series with v shunt S and the rheostat R in series with shunt S. After the motors are started the resistances and 11 are gradually cutout, the series fields are short-circuited, and resistances gradually introduced into the shunts, any or all, to suit the maximum degree of acceleration desired. These switching operations are performed by controller 3. The resistances and the field of each motor may be successively or simultaneously operated. The controller also eflects the reversal of the motors and introduces in one direction of moi-ion more resistance into one shunt-rheostat than in the other to secure a difference in speed in alternate directions of motion of the motors. Such operation of the controller is limited voltage that it will not augment. or 2. In mechanism for variable-speed driv-.I3

speed of t e two motors is thereby well understood and need not be gone into in detail. The degrees of s eed acceleration thus obtained in this first p ase ranges in the minimum speeds from full resistance in circuit with armatures and fields and no resistancein the shunts to the maximum speeds, where the resistances and fields in the armature-circuits are cut out and the limit res stance in the shunts thrown in.

The intermediate or second phase of the variable-speed driving is illustrated in Fig. 3, showing by diagram the connections of the electrical machines still acting as motors when either the controller 3 (or a manual switch) has thrown the armatures and fields circuit from series into parallel. motor is etting the full line volta e, and the largely accelerated. The variations in the degree of the augmented speed of the second phase with the motors 1n parallel are obtained in the same manner as described in connection with the first phase or series arrangement of motors. u

In the final phase of variable speed driving the controller 3 (or a'manual-switch) is arranged to convert one electric machine, as 9, which had previously been runni as a motor, into a generator byreversing tie connections-of the armature or field and lacing said converted enerator in series with the other motor an also in serieswith the generator or enerators supplying current to the line, the s unts remaining in arallel. Thisconversion may take place with the motors I previously in series or in parallel. In this last phase the resistances in the armature and the shunt of the enerator or converted motor 9 are adjusted. the controller ormanually, together with t e short-circuiting of the field, whereby variations in the field density are obtained. -The speed variation thus secured ranges from electromagnetic conditions, where generator 9 will generate such Here each assist the pressure from the line-generators,

to a maximum safe density and voltage. This higher voltage is added to the line voltage to operate motor 8 at the maximum power of the generators. The motor-speed is then increased from full resistance in the armature and field and no resistance in the shunt to successive increased speeds, ending with no resistance in the armature, a shortcircuited .series field, andfull resistance in the shunt. speed variations obtainable in the use of the two electric machines-range through all the accelerations permissible in the series arrangement of the motors, all those obtained by the parallel disposition, and all those secured in the converted motor or generator arrangement added together, or any combination thereof.

While our invention has been described in connection with compound-wound electric machines, yet we contemplate the use of series-wound or shunt-wound electric machines in soiar as they may be applicable and operative. More than two. electric machines may be'used,-if desired. The shunt fields may be arranged in series as well as parallel. This system of variable-speed driving will give excellent results by using two commercial non-variable-speed motors. It will be noted that. the present invention provides by simple means a large number of variations in accelerating and retardin motions for driving machines. Each 0 the phases of acceleration with its variations may be standardized into defined speed ratios. Thus, for eicample, the range may be s stematized into, say, five standard spee s or any other practical manner. 7

It must be understood that the invention isnot confined to the operation of a reci rocating part of a machinebeforedescri ed. This moving art may be rotaryas, for instance, the rive or power shaft of a machine. In the case of a rotary moving mem- 15 It will thus be seen that the her the direction of motion may be in one direction continuouslywithperiods of acceleration, or the direction of motion may be alternately reversed, withvariations in speed driving.

By the terms fields F and F. and the shunts S and S in the specification and claims is meant the series field and shunt field windings on the electric machines 8 and ing, a driven member, two electric machines connected therewith, and means for connecting said machines with a source of electrical.

power as motors and for connecting one of said machines wlth such source as a generator and the other as a motor.

ing, a driven member, two electric machines constantly connected therewith, and means for connectingv said machines with a source of electrical power as motors and for connecting one of said machines with such source as a generator and the other as a motor.

3. In mechanism for variable-speed driving, a driven member, two electric machines mechanically connected together and with said driven member, and means for successively connecting both of said machines with a source of electrical power as motors in series, in'parallel, and for connecting one of said mach nes with such source as a motor and the other as a generator impelled by the first machine to act as a booster.

4. In mechanism for variable-speed driving, a driven member, two electric machines mechanically connected together and to said member, and means for successively placing said machines in series and in parallel as -moto rs and for then connecting one of the I machines as a motor and the other as a generator, and for varying the field resistance of said machines in any of these connections.

In testimony whereof we have affixed our signatures in the presence of two witnesses.

VICTOR O. STROBEL. ARTHUR E. HOGREBE.

Witnesses:

J HN S. RoBERTs, W. R. HUMMEL, 

